Lipid & Lipoprotein Processing Part 3 - Formation of LDL and HDL

this is the third video in the series on lipid and lipoprotein processing today let's discuss the formation of LDL and HDL in the previous video we left off with a newly formed LDL molecule notice that the Apple protein for LDL is Applebee 100 most body cells have receptors for Applebee 100 that allow the LDL to attach to and enter cells LDL entry occurs by a process known as receptor mediated endocytosis once inside the cell the cholesterol from LDL can be used in making plasma membranes for myelin surrounding neurons and for the synthesis of steroid hormones such as cortisol aldosterone estrogen and testosterone excess cholesterol is added to the free cholesterol pool located inside the cell when LDL cholesterol is high in the blood body cells also emit may receive excess amounts of cholesterol luckily the body has a way to remove this excess cholesterol a protein called a PO a 1 is floating around in the plasma and is produced by the liver and small intestines on body cells that are rigid receptor called ATP binding cassette or abca1 this receptor will bind to a PO a 1 doing this will allow a PO a 1 to remove some cholesterol from the free pool inside the cell the a boy 1 also picks up some phospholipids from cell membranes and then becomes what is called a nascent HDL l cat or lecithin cholesterol acyl transferase is an enzyme produced by the liver and is located in the plasma ELQ a tax on free cholesterol in the nascent HDL and converts it into a steroid cholesterol this action removes exposed hydroxyl groups to make a more hydrophobic form of cholesterol called a cholesterol ester without the hydroxyl groups the esterified cholesterol will fall to the center of the nascent HDL to form a mature larger spherical HDL c ET p or cholesterol ester transfer protein allows HDL and VLDL to swap triglycerides and cholesterol esters inhibitors of CET P have been developed and lead to increased HDL levels and lower LDL levels however several medications in this class have failed to produce clinically positive cardiovascular outcomes an asset rap hip was showing some promise but in October of 2017 Merck decided that the clinical profile of anisotropic does not support regulatory filings and decided to cut its losses and move on ultimately HDL travels to the liver where the cholesterol esters from the HDL can be utilized by the liver to make bio here now is a summary of the exogenous chylomicron pathway the endogenous VLDL pathway and the formation of HDL thanks for watching

Channel: PhysioPathoPharmaco

Views: 18,361

Rating: 4.9448276 out of 5

Keywords: lipid, APO CII, apoB100, LDL, triglycerides, animation, video, VLDL, HDL, chylomicron, APOe

Id: PQcJRvbBI8M

Length: 4min 18sec (258 seconds)

Published: Mon May 14 2018